Attach flat mesh (or curve) to another mesh
You could use a displacement modifier with the image texture. 

Some examples of this are: Extrude the outside of a cylinder using a grayscale image, Creating a large landscape with accurately varied elevations and Landscape topography from grayscale image, 

Given that you want to avoid changing the inside shape of the bottle, this might be useful, because it describes how only one side of the solid can be influenced: How to make a perfectly flat bottom for 3D-printing topographic relief?